Gas turbine engines typically include a compressor section, a combustion section and a turbine section, with an annular flow path extending axially through each. Initially, air flows through the compression section where it is compressed or pressurized. The combustors in the combustion section then mix and ignite the compressed air with fuel, generating hot combustion gases. These hot combustion gases are then directed by the combustors to the turbine section where power is extracted from the hot gases by causing turbine blades to rotate.
Some sections of the engine include airfoil assemblies comprising airfoils (typically blades or vanes) mounted at one or both ends to an endwall. Air within the engine moves through fluid flow passages in the airfoil assemblies. The fluid flow passages are defined by adjacent airfoils extending between concentric endwalls. Near the endwalls, the fluid flow is adversely impacted by a flow phenomenon known as a horseshoe vortex, which forms as a result of the boundary layer separating from the endwall as the gas passes the airfoils. The separated gas reorganizes into the horseshoe vortex. There is a high loss of efficiency associated with the vortex, and this loss is referred to as “secondary” or “endwall” loss. Accordingly, there exists a need for a way to mitigate or reduce these endwall losses.